| 1. |
- Brusheim, Patrik, et al.
(author)
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Multiterminal multimode spin-dependent scattering matrix formalism: Electron and hole quantum spin transport in multiterminal junctions
- 2008
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In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 78:8
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Journal article (peer-reviewed)abstract
- We present a derivation of a scattering matrix method providing an exact multimode solution to spin-dependent quantum transport in multiterminal structures. The method is formulated in a general language such that it can readily be applied to any spin-S system with spin interactions. We apply the formalism to spin-1/2 electron and spin-3/2 hole transport in three- and four-terminal structures. It is shown that the existence of a third lead lifts constraints on the flux polarization of two-terminal electron transport. A spin-rectification property in a three-terminal system with Rashba spin-orbit interaction is demonstrated. We furthermore find that a four-terminal structure can partition a fully spin-polarized electron flux into two oppositely polarized fluxes. For holes, we calculate the polarization vector of both the injected states as well as the outgoing states in a three-terminal structure. Close to the onset of propagating channels, the hole polarization exhibits peak-dip structures attributed to the angular-momentum dependent Fano resonances in the three-terminal junction. We rigorously show that when the outgoing state is restricted to a single channel, the polarization is uniquely determined by the outgoing lead state, independent of the scattering details of the structure.
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| 2. |
- Csontos, D., et al.
(author)
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Lande-like formula for the g factors of hole-nanowire subband edges
- 2008
-
In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 78:3
-
Journal article (peer-reviewed)abstract
- We have analyzed theoretically the Zeeman splitting of hole-quantum-wire subband edges. As is typical for any bound state, their g factor depends on both an intrinsic g factor of the material and an additional contribution arising from a finite bound-state orbital angular momentum. We discuss the quantum-confinement-induced interplay between bulk-material and orbital effects, which is nontrivial due to the presence of strong spin-orbit coupling. A compact analytical formula is provided that elucidates this interplay and can be useful for predicting Zeeman splitting in generic hole-wire geometries.
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| 3. |
- Csontos, D., et al.
(author)
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Spin-3/2 physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings
- 2009
-
In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 79:15
-
Journal article (peer-reviewed)abstract
- We present a detailed theoretical study of the electronic spectrum and Zeeman splitting in hole quantum wires. The spin-3/2 character of the topmost bulk-valence-band states results in a strong variation in subband-edge g factors between different subbands. We elucidate the interplay between quantum confinement and heavy-hole-light-hole mixing and identify a certain robustness displayed by low-lying hole-wire subband edges with respect to changes in the shape or strength of the wire potential. The ability to address individual subband edges in, e.g., transport or optical experiments enables the study of hole states with nonstandard spin polarization, which do not exist in spin-3/2 systems. Changing the aspect ratio of hole wires with rectangular cross section turns out to strongly affect the g factor of subband edges, providing an opportunity for versatile in situ tuning of hole-spin properties with possible application in spintronics. The relative importance of cubic crystal symmetry is discussed, as well as the spin splitting away from zone-center subband edges.
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| 4. |
- Stacey, Glyn N, et al.
(author)
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Stem cell culture conditions and stability : a joint workshop of the PluriMes Consortium and Pluripotent Stem Cell Platform
- 2019
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In: Regenerative Medicine. - : Future Medicine Ltd. - 1746-0751 .- 1746-076X. ; 14:3, s. 243-255
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Journal article (other academic/artistic)abstract
- Human stem cells have the potential to transform medicine. However, hurdles remain to ensure that manufacturing processes produce safe and effective products. A thorough understanding of the biological processes occurring during manufacture is fundamental to assuring these qualities and thus, their acceptability to regulators and clinicians. Leaders in both human pluripotent and somatic stem cells, were brought together with experts in clinical translation, biomanufacturing and regulation, to discuss key issues in assuring appropriate manufacturing conditions for delivery of effective and safe products from these cell types. This report summarizes the key issues discussed and records consensus reached by delegates and emphasizes the need for accurate language and nomenclature in the scientific discourse around stem cells.
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